Did you know? The Togean Islands babirusa is the largest of the babirusa species.
B. togeanensis is confined to the Togean Archipelago in Indonesia, between the northern and eastern Sulawesi peninsulas. The species is found on the islands Batudaka, Togean, Talatakoh and Malenge. Recently, their tracks were also reported from Kadidiri Island, a small island north of Togean Island.
B. togeanensis is the largest of the three babirusa species. It has sparser, shorter body than B. babyrussa and, in contrast to B. celebensis, the tail tuft is well developed. The upper canines of males are this species’ most distinctive feature: they are short, slender, rotated forwards and always converge. The frontal furrows on the skull are always shallow, with sloping edges. It is endemic to the Togean Islands, an island group that has been separated from the adjacent eastern arm of Sulawesi for ca. 12,000 years. This suggests that the babirusas from the eastern arm of Sulawesi should be closely related to the Togean animals, but an absence of specimens makes this impossible to test. It cannot be ruled out that Togean babirusas were introduced to the Togean Islands by people, but just as likely, the species swam to these islands.
Even though B. togeanensis is the largest of the babirusa species, it was initially characterized by its small teeth, especially the third molar. Further study showed that compared to the other species, B. togeanensis has relatively large premolars, especially P3, P4, and P3.
Babirusa generally inhabit tropical rain forest on the banks of rivers and ponds abounding in water plants. The natural vegetation on the Togean Islands consists of wet forests of variable types, frequently differing from one island to another, and ranging from monsoon to evergreen. B. togeanensis has also been sighted in mixed gardens, regrowing scrub on former slash-and-burn cultivation fields, secondary forest, village edges, freshwater swamps, and beaches. On Malenge and Kadidiri Islands, the species is most frequently sighted when moving through coconut plantations.
B. togeanensis reportedly feeds on rhizomes, fallen fruits (e.g. Pangium edule, Dracontomelon sp., Mangifera sp., Artocarpus sp., Spondias dulcis, and also, tamarinds, and cacao, as well as annual herbs and vegetables. The species is also reported to feed on coconut but it is unclear whether it eats the shoots of young trees or the fallen fruits.
During interview surveys on the Togean Islands, most respondents (68.2 %) reported encountering B. togeanensis in the morning, between 06.00 to 10.00 am. The reported observations of the species included various activities during that time, such as foraging, mating, wallowing, and resting.
Movements, home range and social organisation
In interviews, 37 % of the respondents mentioned that B. togeanensis is a solitary animal, while 29.6 % of those questioned reported that the species is gregarious, and usually composed of one adult pair with a litter. 29.5 % of the respondents reported group sizes of more than 5 individuals, and these were typically composed of an adult male with multiple females and a litter.
Nothing is known about the breeding behavior of B. togeanensis, but it is assumed to be similar to the much better known B. celebensis. Litter size as observed by local farmers is 2–3 young.
Status and conservation
Babirusa on the Togian islands are susceptible to habitat loss due to forest clearance and forest fires, to disturbance by humans, occasional hunting by the local people if perceived as a threat to crops and predation by dogs. Hunting for food only occurs in a few non-Muslim village communities. In 1998, two thirds of Malenge Island’s forest was damaged by fire. No large animal carcasses were found and babirusas have been seen in several of these localities since, but the fire may have impacted food availability for the species.
In 1978, the population on the Togean Islands was estimated in the region of 500 to 1,000 individuals. Recent estimates place the upper limit of population size at about 500. Recent estimation from questionnaires showed local residents did not provide agreement on population size (ranges from <100 to >1,000), but the interview surveys did suggest that at least between 1995 and 2000 there had not been a sharp population decline.
The species is listed by The IUCN Red List as Endangered, because its extent of occurrence is less than 5,000 km², its distribution is severely fragmented, and there is continuing decline in the extent and quality of its habitat; and because its population size is estimated to number fewer than 2,500 mature individuals, there is an observed continuing decline in the number of mature individuals, and no subpopulation contains more than 250 mature individuals.
Text adapted from: Meijaard, E., J. P. d'Huart, and W. L. R. Oliver. 2011. Family Suidae (Pigs). Pages 248-291 in D. E. Wilson, and R. A. Mittermeier, editors. Handbook of the Mammals of the World. Vol 2. Hoofed Mammals. Lynx Edicions, Barcelona, Spain.
Akbar, S., M. Indrawan, M.P. Yasin, J. Burton & J. Ivan. (2007). Status and conservation of Babyrousa babyrussa in the Togean Islands, based on direct observations and questionnaire surveys (intermittently, 1990 - 2001). Suiform Soundings 7: 16-25.
Groves, C.P. (2001). Mammals in Sulawesi: Where did they come from and when, and what happened to them when they got there? Pp. 333-342 in Faunal and floral migration and evolution in SE Asia-Australasia, edited by I. Metcalfe, J.M.B. Smith, M. Morwood, and I. Davidson. Lisse, The Netherlands: A.A. Balkema Publishers.
Hart, C. (2009). Sulawesi. http://www.mammalwatching.com/Oriental/Otherreports/CH%20Sulawesi%202008.doc.
Ito, M., H. Nakata, I.M. Jaga & I.W. Balik. (2005). Status of Togian babirusa (Babyrousa babyrussa togianensis) on Malenge Island, Central Sulawesi. Pp. 71-77 in Kumpulan makalah seminar sehari peduli Anoa dan Babirusa Indonesia, edited by N. Sugiri, A.H. Mustari, I.S. Suwelo, and I. Djuwita. Bogor, Indonesia.
Macdonald, A.A., J. Burton & K. Leus. (2008). Babyrousa togeanensis. in IUCN 2010. IUCN Red List of Threatened Species. Version 2010.1. Downloaded on 06 April 2010.
Meijaard, E. & C. Groves. (2002a). Proposal for taxonomic changes within the genus Babyrousa. Asian Wild Pig News 2.
—. (2002b). Upgrading three subspecies of babirusa (Babyrousa sp.) to full species level. Asian Wild Pig News 2.
Selmier, V.J. (1983). Bestandsgrosse und verhalten des hirschebers (Babyrousa babyrussa) auf den Togian Inseln. Bongo 7: 51-64.